fix(vts): fix shebang position and variable quoting in init-kvstores.sh

- Move shebang to first line to fix SC1128 error
- Add proper quoting to variable in sqlite3 command to fix SC2086 error

Addresses shellcheck violations found during bash script review.

Signed-off-by: Kallal Mukherjee <[email protected]>

Author: kallal79

vts/test-harness/init-kvstores.sh

@@ -1,13 +1,12 @@
+#!/bin/bash
 # Copyright 2022-2023 Contributors to the Veraison project.
 # SPDX-License-Identifier: Apache-2.0
-#
-#!/bin/bash
 
 set -eux
 set -o pipefail
 
 for t in en ta po
 do
     echo "CREATE TABLE kvstore ( key text NOT NULL, vals text NOT NULL );" | \
-        sqlite3 $t-store.sql
+        sqlite3 "${t}-store.sql"
 done